The present invention relates to a new, novel, and distinct variety of apple tree, and which has been denominated varietally as ‘Regal D5-100,’ and more specifically, to a novel apple tree with an upright growth habit with moderate vigor that may be pollinated from any other diploid apple of a mid-season bloom. The novel apple tree also produces fruit that are medium in size and that have streaked bi-color, that are slightly lopsided, and that exhibit four months of common storage life.